1. Field of the Invention
This invention relates to an oil separator for separating engine lubricating oil from blow-by gas recycled back to engine combustion chambers through an intake system.
2. Description of the Prior Art
Modern automotive engines including gasoline-fueled engines and diesel engines are usually provided with a so-called PCV (Positive Crankcase Ventilation) system for the purpose of exhaust emission control. The PCV system consists of a PCV valve which is disposed in a blow-by gas recirculation line connecting a crankcase chamber (or a cylinder head cover chamber) and an intake manifold to control the amount of the recycled blow-by gas, so that the blow-by gas leaking within the engine is recycled back to engine combustion chambers via an intake system. In such a PCV system, if the blow-by gas is recycled as it is, engine lubricating oil in the state of mist and carbon particles contained in the blow-by gas will be adhered to the inner wall surface of pipings and various control members of engine control systems exposed to the recycled blow-by gas, thereby giving rise to various problems in engine control. In order to prevent such problems, it has been already proposed to provide an oil separator in the blow-by gas recirculation line downstream of the PCV valve to separate the lubricating oil mist and the carbon particles. A variety of oil separators are put into practical use in which most ones employ baffle plates and/or steel wool as an oil separating element. However, such oil separators are lower in oil separating efficiency, thereby still leaving the above-mentioned problem due to lubricating oil mist and carbon particles. In this regard, it is eagerly desired to obtain an oil separator of a high oil separating efficiency.